• Transactions on Electrical and Electronic Materials
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• 제2권4호
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• pp.11-14
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• 2001

Phase intergrowth in BSCCO thin films has been Investigated. It turfed out from XRD analyses of these phases that molar fraction of each constituent phase in the intergrowth thin film can be exhibited as a function of substrate temperature and ozone pressure. Super- conducting behavior of the intergrowth thin aim Is also discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.327-330
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• 2001

Phase intergrowth in BSCCO thin films have been investigated. It turned out from XRD analyses of these phases that molar fraction of each constituent phase in the intergrowth thin film can be exhibited as a function of substrate temperature and ozone pressure. Superconducting behavior of the intergrowth thin film is also discussed.

• 한국전기전자재료학회논문지
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• 제15권8호
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• pp.736-741
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• 2002

Phase intergrowth some kinds of the $Bi_2Sr_2Ca_{n-1}Cu_nO_y$ phases is observed in the thin film fabrication at ultralow co-deposition with multi targets by means of ion beam sputtering. The molar fraction of the Bi2212 phase in the mixed crystal of the grown films is investigated as a function of the applied ozone pressure and the substrate temperature. The activation energy for the phase transformation from the Bi2201 to the Bi2212 is estimated in terms of the Avrami equation. This study reveals that the formation of a liquid phase contributes significantly to the construction of the Bi2212 phase in the thin films, differing from the bulk synthesis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.490-493
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• 2002

Phase intergrowth some kinds of the Bi$_2$Sr$_2$Ca$\_$n-1/Cu$\_$n/O$\_$y/ phases is observed in the thin film fabrication at ultralow co-deposition with multi targets by means of ion beam sputtering. The molar fraction of the Bi2212 phase in the mixed crystal of the grown films is investigated as a function of the applied ozone pressure and the substrate temperature. The activation energy for the phase transformation from the Bi2201 to the Bi2212 is estimated in terms of the Avrami equation. This study reveals that the formation of a liquid phase contributes significantly to the construction of the Bi2212 phase in the thin films, differing from the bulk synthesis.

• 한국초전도ㆍ저온공학회논문지
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• 제24권4호
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• pp.25-28
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• 2022

We investigated the formation of superconducting intergrowth phases through the interface reaction both between TlSr₂Cu₁O₅ (Tl-121) and (CrO₄)Sr₂CuO₂, and between Tl -121 and ((CO₃)_0.5(CrO₄)_0.5 Sr₂CuO₂ phases. We found oxychromate intergrowth phases can be formed through the interface reactions and a new superconducting oxychromate compound TlSr₄Cu₂O_z(CO₃)_0.5(CrO₄)_0.5 with T_c above 73 K was discovered based on the results of the interface reactions.

• Transactions on Electrical and Electronic Materials
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• 제5권5호
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• pp.199-203
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• 2004

Superconducting B $i_2$S $r_2$C $a_{n-l}$C $u_{n}$ $O_{x}$(n=2～4) thin films were prepared by single target DC-magnetron sputtering. And, that was compared with the B $i_2$S $r_2$C $a_{n-l}$C $u_{n}$ $O_{x}$(n=1～3) thin film fabricated by using the ion beam sputtering. Phase intergrowth among n=2-3, 3-4 and 4-5 phases was observed. The molar fraction of each phase in the mixed crystal of the deposited films was determined by x-ray diffraction analyses and investigated as a function of $O_2$ gas pressure during sputtering. We investigated the changes of the superconducting properties by molar fraction of each phase. Also, the thin film surface observation was carried out by atomic force microscope. The images show the average particle size decreases, and the distribution density of particles on the film surface was to increase with lower gas pressures. The fabrication conditions for selective growth of the single n=2, 3 and 4 phases in BiSrC $a_{n-l}$C $u_{n}$ $O_{x}$(n=2～4) thin film are discussed.e discussed.ussed.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2761-2764
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• 2011

A new Ruddlesden-Popper phase $NdSr_2MnCrO_7$ has been prepared by the standard ceramic method. The powder X-ray diffraction studies suggest that the phase crystallizes with tetragonal unit cell in the space group I4/mmm. The electrical transport properties show that the phase is an electrical insulator and the electrical conduction in the phase occurs by a 3D variable range hopping mechanism. The magnetic studies suggest that the ferromagnetic interactions are dominant.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 1994년도 제25회 학술대회 연제 초록
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• pp.31-31
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• 1994

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1679-1683
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• 2013

Intergrowth perovskite type complex oxides $La_{0.8}Ln_{0.2}Sr_2MnCrO_{7-{\delta}}$ (Ln=La, Nd, Gd, and Dy) have been synthesized by sol-gel method. Rietveld profile analysis shows that the phases crystallize with tetragonal unit cell in the space group I4/mmm. The unit cell parameters a and c decrease with decreasing effective ionic radius of the lanthanide ion. The magnetic studies suggest that the ferromagnetic interactions are dominant due to $Mn^{3+}$-O-$Mn^{4+}$ and $Mn^{3+}$-O-$Cr^{3+}$ double exchange interactions. Both Weiss constant (${\theta}$) and Curie temperature ($T_C$) increase with decreasing ionic radius of lanthanide ion. It was found that the transport mechanism is dominated by Mott's variable range hopping (VRH) model with an increase of Mott localization energy.

• 대한화학회지
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• 제51권2호
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• pp.178-185
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• 2007

펜타실 구조와 유사한 제올라이트형 결정성 보로실리케이드를 수증기 쪼임법으로 제조하였다. 실제 여러 종류의 서로 다른 붕소화합물 원료를 사용하여 만든 다양한 조성의 Na2O.SiO2.B2O3.TBA2O 겔을 건조시켜 얻은 무정형 분말을 수열합성 분위기에서 수증기를 쪼임으로써 펜타실 구조를 갖는 보로실리케이트 제올라이트를 합성하였다. 이때 MFI와 MEL 구조가 90:10의 비율을 혼합되어 있는 새로운 중간구조 물질이 얻어 졌다. 본 연구로부터, 젖어 있는 반응성 고체상 물질이 수증기와 높은 pH 분위기에서 결정화가 이루어짐을 확인하였다. X-선 회절법으로 분석한 결과 생성물은 우수한 결정성을 가질뿐만 아니라 독특한 촉매적 성질을 보일것으로 예상되는 구조를 갖는다. 또한 반전중심을 갖는 MFI 구조의 펜타실 층이 규칙적으로 쌓이는 모양을 보이지만 이는 MEL 구조의 거울상 층으로 이루어진 결함에 의해 방해된다. 생성물은 77 K 질소흡착법에 의하면 미세기공 부피가 0.160 cc/g 로서 순수한 MFI 구조 물질이 갖는 0.119 cc/g 보다 더 크며, 비교적 넓은 비표면적(~600 m2/g)을 보인다. 적외선 스펙트럼에서는 900.75 cm-1에서 흡수띠를 보이는데, 이는 붕소가 결정성 실리케이트의 사면체 구조내에 위치함을 뜻한다.